Inventories - Inventories (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Mar. 31, 2013
Inventory Disclosure [Abstract]
Finished goods	$ 54	$ 1,024
Work in process	9,112	7,350
Purchased and manufactured parts	18,539	12,532
Inventories, gross	27,705	20,906
Reserve for slow moving and obsolescence	(3,781)	(3,116)
Total	$ 23,924	$ 17,790